Apparatus for recovering pulp from printed paper.



R. D. CARTER.

APPARATUS FOR RECOVERING PULP FROM PRINTED PAPER.

APPLICATION FILED DEC-l4, I915- Patented June 27, 1916.

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Specification qr Letters Patent. t t a June 2'1 11 at a.

Application filed December 14,1915. I sea-11a. saw.

To all whom it may concern Beit known that I, ROBERT D. CARTER, acitizen of the United States, residing at Wanaque, county of Passaic,and State of New Jersey, have invented certain new and usefulImprovements in Apparatus for Becovering ulp from Printed Paper, fullydescribed and represented in the following specification and theaccompanying drawin s, forming a part of the same.'

his invention relates to a means for treating printed paper to removethe ink therefrom and produce a pulp which can be used again tomanufacture white paper.

It is comparatively easy to treat soft paper, like printed newspaper,toremove the ink therefrom, but the same treatment will not efi'ectuallyloosen and remove the ink from hard sized papers, like some bookpapers;and I have therefore devised the present invention to accomplish thatresult. It has been common to out such papers into small fragments andfeed the same in a heated state to a rotary devil with a considerableproportion of soda-ash, so as to affect the paper chemically andmechanically in its passage through the devil; and the devil is soconstructed as to discharge the material rapidly, so that it issubjected but a short time to the disintegrating action of the teethupon the drum and casing of the devil, and such treatment is whollyinadequate to remove printers ink from hard sized papers. I

To completely effect the removal, I combine with the devil or similardisintegrator a horizontal cylindrical digester having.

means, as rotary arms, for mixing or rubbing its contents, with aheatingtank interposed between the devil and the digester, and connectedwith both and serving to reheat the pulp that is discharged from thedevil, and deliver it in a highly heated state to the lower part of thedigester. After the pulp has passed through the digester it is deliveredfrom the upper part of the same, thus keeping the digester solidly fullof the stock under treatment. This is not the case with the deviloperated in the usual manner, in which the stock is fed into the upperpart of the casing and discharged from the lower part, so that it movesrapidly through the.

steam caiinot be injected into the casing of the devil 'or the casing ofthe digester which I connect thereto, as the steam entering the casingtends to scatter the stock and force 1t backward tothe inlet or forwardto the outlet, so that the stock is not fully subected to the action ofthe disintegrating agents. The heating-tank is interposed between thedevil and digester so as to thoroughly reheat the stock discharged fromthe devil, before it is subjected to treatment in the digester wheresteam cannot be advantageously mtroduced. Owing to the use of a conlcaldrum'in an ordinary devil, very little space is left between the drumand casing for the passage of the stock, and I secure a much longertreatment of the stock in the digester which I employ, by making itthree or four times the capacity of the devil so that the material movesthrough the same three or four times more slowly, and is thus subjectedmuch longer to the chemical and mechanical agencies. By combining theheating-tank and the cylindrical digester with the devil, I am enabledto reduce the stock to fine pulp, and loosen the particles of inktherefrom, so that a suitable after-treatment readily separates the inkfrom the fibers. An additional washing operation with a suitablebleaching agent can thus produce stock entirely white.

The invention will be understood by reference to the annexed drawing, inwhich Figure 1 is a side elevation of the apparatus with the top casingnear the top of the steam-tank broken away; Fig. 2 is a plan of theapparatus with one corner of casing upon the devil broken away; and Fig.3 is a section of one of the elbow connections to or from the tank, witha steam injector applied thereto; Fig. 4 is an end view of the digester.The devil is shown with the usual conical casing a and conical drum 6,each having teeth 0 thereon to tear and disintegrate the stock. The drumis revolved by a shaft 1).

The casing is shown with a hopper d and inlet at its smaller end and anoutlet-pipe 0 connected near its larger end, and extended to the lowerpart of the heating-tank 7". An elbow e is shown upon the pipe 6 with asteam-pipe 8 connected to its outer side, as shown in Fig. 3', anddirecting a jet of steam toward the inlet of the heating'tank, so as toforce the stock from the pipe into thorough mixing of the contents, bydriving the same around.

The heating-tank is shown with an open vapor-outlet g in the top,beneath which a bafiie-plate h is secured to prevent any solid matterbeing blown out from the boiling mass in the tank, which usually standsat the level i above the outlet-pipe y. This pipe is taken from the sideof the tank intermediate to the steam-inlet and steam-outlet, and isconnected to the lower part of the disintegrator-casing k. This casingis formed cylindrical, with a row of prongs I at each side ofthe center,and is provided with a central shaft m carrying a series of hubs n eachhaving two opposite arms 0 which rotate between adjacent prongs Z.

It will be noticed in Fig. 4 that the prongs and arms are made verynumerous and fitted close -to one another so as to most forcibly rub thefibers which pass between them, and thus remove the ink from the stockby abrasion rather than by chemical action. This saves much alkali andthe weakening of the stock by chemical action. To prevent the stock fromevading the action of the rotating arms, they are extended as nearly aspracticable tothe inner wall it is' obvious that the construction of thearms is adapted to contact with the stock and rub it most effectively.

The shaft is fitted to stufiing-boxes 9 upon the heads of the casing andis also supported in bearings 9 attached to the heads, and has a pulleyp for rotating it. An outlet 1' is shown near the upper edge of one ofthe heads [6 at the opposite end from the inlet 3', and the stockentering the casing upon its lower part, thus fills the casing before itcan be discharged from the outlet 1', and is therefore solidly incontact with the prongs Z and arms 0 during its passage through thedigester. To facilitate the connection of the digester with other partsof the apparatus, each head is formed with three holes marked 1, 2 and 3in Fig. 4, any of which holes not required for connections being closedby a blank flange. The hole 1 close to the top of the casing serves forthe outlet, and the hole 2 or 3 upon either side of the bearing 9 may beused for the inlet, as proves most convenient, the pipeflange 4 over thehole 2 serving to connect the pipe 3' in. that figure. A supply-pipe tis shown over the hopper d of the devil, by which the divided stock isfed into the soda-ash solution. 7

The operation of the entire apparatus is as follows: The conical form ofthe devil induces a centrifugal movement of the stock and drives it tothe larger end of the casing iafrom which it escapes by the pipe 6. Fromthis pipe it is delivered into the lower part of the heating-tank f,where steam is admitted by the pipe f to give the stock a thoroughheating on its passage to the diester-casing 70. When required, steammay lie introduced into the pipe 6 by the injectorpipe 8 to drive thestock forward. The pipe 7' discharges the stock from the heating-tank ata considerable distance above the bottom, so that the tank must fill upto that-level, or higher, before it will operateby gravity to move intothe lower part of the casing 70. In suchmov'ement through the pipe j,

.steam may be introduced into the pipe by a steam-pipe s to drive thematerial forward. In the casing k the material is forced to fill thecasing from the bottom to the outlet before it is discharged, and as itscapacity is many times greater than that of the small space between thedrum and the casing of the devil, the'stock moves slowly from theinlet-end to the outlet-end of the digester, and is thus kept solidly incontact with the arms 0, which in cooperation with the teeth Zthoroughly mix the stock and beat it so as to loosen the ink therefrom,and mix it with the alkali. The soda-ash thus operates during the timethe stock is moving through the digester, to loosen and separate the inkfrom the fibers, so that when the stock is delivered from the digesterthe ink can be wholly separated by a suitable washing and settling.

The invention includes the treatment of the stock mixed with heatedalkaline solution, first in a disintegrator where the stock may beviolently torn and the fibers separated from one another, and beaten atsuch velocity as to partly loosen the ink, then reheating the stock, asdescribed, and further subjecting it to mechanical and chemicaltreatment in the digester, to loosen the ink from the fibers and rub theparticles of ink therefrom, such digester having mixingarms rotatedclose to stationary prongs, and

level to discharge the stock more freely to the tank and digester.

The use of steam-injectors in the connecting-pipes, by their propellingforce, permits the setting of the several parts at nearly the samelevel, if desired. The stock may, if required, be subjected to two ormore of the digesters successively, the stock being delivered from theupper part of one to the lower part of the next in the series, so thatthe casing 70 of each digester is filled by the stock before it escapes.

The object of the invention is to remove the printers ink from the paperwith as little injury as possible to the fiber, and the use of as littlechemical as is possible, as any reduction in the chemical not only makesa saving in the expense but leaves the fiber with greater strength.

It will be noticed that the alkali is brought into contact with thefiber mechanically in the digester, and the continuance of this contact,for the length of time it can be practised in the digester, renders thealkali so much more eifective, that I find in practice only twothirds ofthe alkali heretofore used is required in the use of my improvedapparatus. It will be noticed that the casing is provided with prongs Zonly at its opposite sides, and the shaft in like manner has arms onlyupon its opposite sides. With this construction the arms pass betweenthe have pointed out that my arms differ from those heretofore used inoperating close to the prongs upon the casing and in extending betweenthose prongs almost into contact with the inner wall of the casing, sothat the pulp and stock thrown outward against such wall by centrifugalforce cannot escape the rubbing operation of the arms; which is designedto, and does in practice, remove the ink from the fiber largely bymechanical action, thus avoiding the use of so much alkali.

Having thus set forth the nature of the invention what is claimed hereinis: i

1. The combination, with a devil or similar disintegrator. and ahorizontal cylindrical digester havin means for mixing its contents, ofa heating-tank intermediate to the devil and the digester and receivingthe pulp from the devil and delivering it to the lower part of thedigester and provided with 2. The combination, with a devil or othersimilar disintegrator and a horizontal cylindrical digester having meansfor mixing its contents, of a heating-tank intermediate to the devil andthe digester and receiving the pulp into its lower part from the deviland discharging the pulp at a higher level tothe lower part of thedigester, and the pulp being delivered from the upper part of thedigester, whereby the digester is kept filled with the hot pulp and itsdelivery regulated by the supply to the devil.

3. The combination, with a devil or similar disintegrator and ahorizontal cylindrical digester having means for mixing its contents, ofa heating-tank intermediate to the devil and the digester and receivingthe pulp into its lower part from the devil'and havlng a supply-pipe atthe bottom and a steam-vent at the top with a baffle-plate adjacent tosuch vent and having an outlet intermediate to the steam-pipe and thevent connected to the lower part of the digester, and the pulpdischarged from the upper part of the digester, as and for the purposeset forth.

4. The combination,- with a devil and a heating-tank having its lowerpart connected thereto by an elbow-pipe, of a cylindrical digesterprovided with means for mixing the contents and connectedto theheating-tank by an elbow-pipe, at least one of the said elbows having asteam-injector applied thereto for propelling the contents from the pipeinto the adjacent receptacle.

5. A digester for continuous mechanical and chemical treatment of paperfiber,

. consisting of the cylindrical casing 70 having a row of prongsprojected inward from each of its opposite sides, a rotary shaft havingarms upon its opposite sides operating between the said prongs, theprongs and arms having their opposed sides near to one another and thearms extended closely to the wall of the casing, and means for supplyingthe stock continuously to the lower. part of the digester at one end anddischarging it continuously from the upper part of the digester at theopposite end.

In testimony whereof I have hereunto set my hand.

ROBERT D. CARTER.

